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| Srl | Item |
| 1 |
ID:
136039
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| Summary/Abstract |
Flow around a conical nose with rounded tail projectile has been studied numerically for subsonic, transonic and supersonic flow regimes. The conic angle of the projectile is 10°. The inflow Mach numbers are 0.5, 0.9, and 1.5. Axisymmetric Euler’s equations are solved for predicting the drag coefficient. It has been observed that even for a subsonic flow regime, the Mach number distribution is not uniform owing to the non-symmetric shape of the projectile. The predicted drag coefficients for subsonic, transonic, and supersonic cases are 0.018, 0.089, and 0.395, respectively. It was observed that rounded tail is a better option than boat tail so far drag force is concerned.
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| 2 |
ID:
177323
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| Summary/Abstract |
Coal consumption and production have sharply declined in recent years in the U.S., despite political support. Reasons are mostly unfavorable economic conditions for coal, including competition from natural gas and renewables in the power sector, as well as an aging coal-fired power plant fleet. Nevertheless, coal remains a major energy source in the North American energy markets. Supplementing EMF34 energy system analyses, we take a sectoral perspective to analyze coal's future role in this context. The U.S. Energy Information Administration as well as most models in EMF34 depict continuously high shares of coal-fired power generation over the next decades in their current policy scenarios. We contrast their results with coal sector modelling based on bottom-up data and recent market trends. We project considerably lower near-term coal use for power generation in the U.S. This has significant effects on regional coal production. Allowing new export terminals along the U.S. West Coast could ease cuts in U.S. production. Yet, exports are a highly uncertain strategy because the U.S. could be strongly affected by changes in global demand, for example from non-U.S. climate policy.
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| 3 |
ID:
115127
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| Publication |
2012.
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| Summary/Abstract |
Because of economic growth and a strong increase in global energy demand the demand for fossil fuels and therefore also greenhouse gas emissions are increasing, although climate policy should lead to the opposite effect. The coal market is of special relevance as coal is available in many countries and often the first choice to meet energy demand. In this paper we assess possible interactions between climate policies and the global steam coal market. Possible market adjustments between demand regions through market effects are investigated with a numerical model of the global steam coal market: the "COALMOD-World" model. This equilibrium model computes future trade flows, infrastructure investments and prices until 2030. We investigate three specific designs of climate policy: a unilateral European climate policy, an Indonesian export-limiting policy and a fast-roll out of carbon capture and storage (CCS) in the broader context of climate policy and market constraints. We find that market adjustment effects in the coal market can have significant positive and negative impacts on the effectiveness of climate policies.
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